The Texas woman who allegedly stabbed her boyfriend with her stiletto heel at least 25 times was defending herself from yet another instance of abuse at the hands of the man she is accused of murdering, her attorney said at her trial's opening arguments today.

Ana Trujillo, 45, is on trial in the death of her on-again, off-again boyfriend, Dr. Alf Stefan Andersson.

The prosecution today told jurors of the couple's contentious relationship in which Trujillo had a history of being angry with Andersson. Prosecutors have alleged that the Houston woman stabbed her already injured boyfriend to death last year by sitting on him and striking him in the face at least 25 times with her stiletto heel.

Police say Trujillo called 911 shortly before 4 a.m. June 9, 2013. When police arrived at the victim’s luxury high-rise apartment, they say, Trujillo answered the door covered in blood.

Inside, police found Anderson, 59, a medical researcher at the University of Houston, in a hallway, with Trujillo’s stiletto next to him, officials say.

“A stiletto heel is not what’s typically used to kill someone. It’s not a knife or a gun, it’s more of a self-defense tool, something you use because that’s all you have,” Abrams said. “The fact that the weapon was a stiletto heel tends to help the defense.”

Prosecutors will argue that Trujillo also smothered and strangled Anderson, trying to prove to a jury that she went too far, Abrams said.

“This is not an easy case for the prosecution,” Abrams said, “which seems to have already conceded that there was some sort of argument that led up to the killing.”

If convicted, Trujillo could face anywhere from 5 years to life in prison.